Hydraulic device and wheelchair equipped therewith



Nov. 5, 1968 c. w. OJA ETAL 3,409,324

HYDRAULIC DEVICE AND WHEELCHAIR EQUIPPED THEREWITH Filed Aug. 22, 1966 im-d 76 24 Wt/E/YTOPS 6424 M 0/4 flow/ 0 A Jam/6mm course, known;

tion, with its rotatable threaded means acting upon a United States Patent Carl W. ()ja Filed Aug. 22, 1966, Ser. No. 573,900

Claims. (Cl. 297-) ABSTRACT OF THE DISCLOSURE The invention is directed to a hydraulic device having an elongated hydraulic pump member with a special sleeve insert defining the lateral surfaces of the hydraulic fluid reservoir thereof. The pump member has a crank receiving recess at one end thereof permitting removal of the pump actuating member from the hydraulic pump. An elongated hydraulic jack member is also provided, preferably also with a sleeve insert defining the lateral surfaces of its hydraulic fluid reservoir. These parts are connected with a flexible hydraulic conduit and the assembly is particularly useful as a part of a wheelchair to facilitate the narrowing thereof for passage through narrow passages (such as some doors).

This invention relates to a new hydraulic device, particularly one having a rotatable threaded means acting upon a piston or the like as the means to effectuate hydraulic flow adjustments. The invention also relates to modified wheelchairs.

The new hydraulic device is especially useful as a modiflcation to wheelchairs to permit narrowing of the width thereof. This is particularly the case where the wheelchairs are of the type having spaced seat-support siderods supported by a collapsible vertically-oriented X- frame. Such wheelchairs have base frame members on which the wheels of the wheelchair are afiixed and on which the collapsible X-frame is supporteduThe X-frarne supports the side-rods between which the seat member of the chair is flexibly stretched and suspended. The new hydraulic device acts upon at least one, and preferably only one, of the spaced seat-support side-rods to effect elevation and lowering of it. Elevation of a spaced seatsupport side-rod effects collapsing of the X-frame toward the vertical to cause contraction or narrowing of the wheel spacing and total width of the wheelchair.

Of course, the new hydraulic device may be used in any of a variety of applications where small adjustments are to be effected in a remote location or an area not conveniently directly accessible.

Hydraulic devices to eflect small adjustments are, of

but the specialized device of this invenpiston to effect adjustments, is believed to be quite out of the main stream of hydraulic art. The feature of rotatable threaded means as an integral part of the hydraulic device permits many advantages not heretofore attained in a single simplified hydraulic device. Power transmission and power capabilities are improved. Illustratively, the rotatable threaded means in the environment of the hydraulic invention permits a rather weak force applied by an individual to be transmitted hydraulically in a manner whereby the individual isable to raise and lower himself with ease. All this is accomplished without cumbersome apparatus or any auxiliary source of power such as an electric motor or other motive source.

The invention will be described by reference to a drawing made a part hereof wherein:

FIGURE 1 is a schematic perspective view, partially 3,409,324 Patented Nov. 5, 1968 ice broken away, of a wheelchair modified with the new hydraulic device for the narrowing function;

FIGURE 2 is a schematic perspective view of the overall new hydraulic device of this invention;

FIGURE 3 is a schematic view in cross-section of the pump member of the new hydraulic device;

FIGURE 4 is a magnification of the section 4-4 FIGURE 3; and

FIGURE 5 is a schematic view in cross-section of the jack member of the new hydraulic device.

The modified wheelchair of the invention is illustrated only in certain respects in FIGURE 1. This chair, in the preferred wheelchair embodiment of the invention, comprises a vertically-oriented X-frame of at least one pair of posts or rods 10 and 11 which are pivotally attached to each other at a point intermediate the ends of the same. These posts are collapsible toward each other and toward the vertical during collapsing or narrowing of the wheelchair. The upper part of each of the posts of the X-frame (or of each pair of posts if more than one pair is employed in the X-frame) supports a horizontallymounted seat-support side-rod 12. For clarity, only one side-rod 12 is shown in the drawing. The seat-support side-rods function, either alone or in combination with other means, as the means for attachment of a flexible seat member 13 therebetween. The seat member 13 is normally stretched between the side-rods when the chair is in expanded operable condition for use, but folds as the chair is narrowed by folding the X-frame toward the vertical.

The lower part of each X-frame post or rod 10 and 11 is mounted to a base frame brace on its respective side of the chair. Each horizontal base frame brace, only one numbered 14 being shown in the drawing, is united with upstanding base frame braces 15 and 16. Near the rearmost of which is attached a post 17, suitably extendible and serving as one of two or more posts or frames for support therebetween of a brackrest (not shown in the drawing), preferably a flexible or collapsible one. Near the foremost brace 15, and usually mounted thereto, is a provision for leg and foot rests or supports (not shown), as is well known.

Normally the base frame is split into two essentially mirror-identical parts, one on each side of the chair, with each half base frame (comprising horizontal brace 14 and vertical brace members 15 and 16 on one side of the chair) being fitted with wheel support hubs or other members for the usual hand-operated wheels 18 and the pivotable follower type wheel or wheels 19. To lend added strength to the chair, it is customary to either employ dual and vertically displaced X-frame members for the chair, or to employ telescopically slidable brace members such as 20 and 21 attached to and depending from the seat-support side-rods into upstanding base frame ele ments 15 and 16, as illustrated. Additional braces ant specialized joints and parts may also be part of the wheel chair.

It should be recognized that the foregoing is onl directed to well-known parts and the arrangement thereo: in wheelchairs currently commercially available.

Such wheelchairs are modified according to this inven tion by a hydraulic device to facilitate the narrowin function of the wheelchair, while it is occupied by at individual, from its normal width to a width up to abor 6 or more inches less than its normal width. Such narrovt ing permits the wheelchair, while occupied, to pa. through narrower doors and openings than capable passing its fully extended width. The need for convel iently operated and reliable narrowing means as part wheelchairs is longstandin and even :acute in the case 1 wheelchairs used in private homes.

out of '(e.g., rod 29) of the wheelchair v32 of the hydraulic jack, or a jack post projection 33, is in position to act upon at least hydraulic pump 22 will now housing 34. This 37, and extends to ofv means, to wheelchair base frame elements (e.g., brace rod 29 between upstanding braces and 16 and the front curved portion of base frame brace rod 14) at a location on the front and side of the seat member of the wheelchair,

,so that the crank member for the hydraulic pump is conveniently operated by an individual occupying the wheelchair. When not in use, the crank member is suitably removed from the pump 22 and placed in a storage recess or tube 31, which is mounted adjacent to the pump 22, preferably as part of the attachment member 23. The

hydraulic jack member 24 is atfixed by means of its attachment brace or other means 25 to base frame elements such that the jack post one of the spaced seatsupported side-rods 12 of the wheelchair, to elevate that side-rod, thereby to cause movement of the X-brace of the wheelchair toward the vertical, i.e., toward a collapsed vertical position. In so doing, the wheelchair is narrowed.

vReferring to FIGURES 3 and 4, the details of the be described. This pump has an elongated outer housing 34, preferably cylindrical. This housing is adapted to be mounted to a base frame element of the wheelchair in essentially vertical orientation and in spaced but fixed condition toward the front and side of the seat member of the wheelchair.

Next, the pump has a hydraulic fluid reservoir in the lower extremity of the cooperates to form the seal.

A port 40 in the lower extremity of the reservoir 35 connects the reservoir to the exterior of the elongated port 40 is suitably located in the plug r a housing attachment 41 for connection the hydraulic hose 26 for conduit access to the reservoir 5 The upper portion of the reservoir 35 is defined by a piston 43 having an O-ring seal 44, suitably analogous to the plug and O-ring seal at the lower terminus of the reservoir. The piston 43 is adapted to slide substantially the entire length of the fluid reservoir 35; but it is not adapted to slide out of the upper terminal limit 45 of the sleeve or cylinder 36 of the reservoir.

" The' pist'on 43 has an annular shoulder at its outer attached in a non-pivotal relationship to each other; they are immovable with respect to each Jther, but move as a unit.

At the removed extremity of connecting shaft 46, .e., at the end of said shaft away from the piston 44, s affixed, as by welding, a nut member 47. Nut member I7 is essentially a solid terminal end for connecting rod 6; but significantly, nut member 47 has an internal bore 8 which is threaded. The threads of the bore 48 cooperate with a threaded bolt member 49. Thus asbolt member 49 is rotated, nut member 47 is moved with respect to bolt member 49. This is accomplished by preventing nut member 47 from fOllOWlng bolt member 49 in rotation; and the means whereby nut member 47 is prevented from rotating. is a pin and slot arrangement. Connecting rod or shaft 46 is provided with an elongated slot 50 (see FIGURE 3). A pin 51 is located in this slot and mounted in ffixed condition in the housing 34. Thus, as bolt member 49 is rotated, nut member,47 is forced to move.(because of the pin 51 and slot 50 arrangement) up and down along the length of bolt 49. Such movement of nut 47 causes the elements connected with it, i.e., the connecting rod 46 and piston 43, to move commensurately'.

To be observed is the fact that the hole for pin 51 is located outside of the path of movement for piston 43. The upper extremity of movement of piston 43 is approximately illustrated in the drawing; and the lowermost extremity of its movement is illustrated by broken lines at location 52 in the drawing. Indeed, as a convenience of manufacture, because it is so different to force an 'O-ring past a slot or hole in a sleeve without damaging it, the cylinder or sleeve 3'6 of the reservoir 35 terminates, as at numeral 45, before the hole 51 is reached. A further support sleeve 53 is preferably located in abutting relationship to the reservoir sleeve 36. This further support sleeve 53 advantageously serves as a cylinder for guiding connecting rod 46 and strengthening the device.

The end of sleeve 53 removed from the reservoir 35 is suitably provided with an internal annular shoulder 54. Located loosely in this shoulder recess is the lower washer 55 of a thrust washer arrangement suitably comprising that lower washer 55, an upper washer 56, and seal or ball-bearing-containing washer 57, Above the thrust washer is a radial bearing having an outer annulus or race 58 which is essentially immovable with respect to the outer shell or housing 34 and essentially immovable washer 56 of the thrust washer. The inner annulus or race 59 of the radial bearing is freely rotatable by means of the ball-bearing action separating it from the outer race 58. Further, to the inner race 59 is rigidly fixed an internally-spliued nut member ,60 cooperatively fits the splined end (not shown in detail) of the crank 30 for rotation of splined member 60.

I I sleeve 61, in cooperation with the splined recess 60 and inner race 64,

tends to prevent jamming of the shaft of crank 30 during rotation of it.

Jack member 24 is illustrated in FIGURE condition, to be consistent with the elevated condition jack member suitably is defined by elements comparable to the elements defining the bottom limits of the pump reservoir, i.e., a plug 67 having a shoulder 68 over which the sleeve 66 of the reservoir cylinder is fitted, an O-ring seal 69, a retaining ring 70 holding the plug 67 in position in the housing 65, and a lower port 71, suitably through the plug 67 to the exterior of the housing 65 for conduit connection between the reservoir of the iack member and the. hose or conduit to the pump member. I

As in the pump member, the cylinder sleeve of the hydraulic reservoir preferably terminates short of any cross-pin hole through the apparatus. Thus reservoir sleeve 66 terminates at numeral 72 in the drawing, with an abutting sleeve 73 extending upwardly therefrom and serving as a guide cylinder for the jack post 32. Pin 74 is lodged in a hole in housing 66 and a hole in sleeve 73 and extends through a slot 75 (cross-section is through the slot 75 in FIGURE 5) in jack post 32. Jack post 32 preferably is sleeve-like in character as distinguished from being solid throughout. Thus, the slot is easily 'formed along a portion of the length of the jack post. Also, the preferred sleeve-like character of the jack post permits the piston 76, which defines the upper limits of the capacity of the hydraulic reservoir in the jack member, to be mounted rigidly to the jack post 32 in a manner analogous to the mounting of piston 43 to the sleeve-like connecting rod 46 in the pump member, i.e., with the sleeve of the jack post 32 extending over and fixed to a shoulder 77 of the piston 76. Suitably rigid connection is accomplished by employing nylon pistons 76 which have an annular shoulder recess 77 that fits very snugly into the sleeve 32. As with the piston of the pump member, an O-ring 78 is used to form a seal between piston 76 and reservoir cylinder 66.

Broken line 79 illustrates the approximate upper limits of piston 76 as the jack post 32 is extended or telescoped out of the housing 65 during pumping of hydraulic fluid from the reservoir 35 of pump 22 to the reservoir of jack member 24. This upper limit of movement is regulated by slots 75 cooperating in sliding fashion with pin 74 until the limit of slots 75 at the lower end of the jack post 32 abuts against pin 74.

A bleeder port 80 is suitably provided in the hydraulic part of the device to allow escape of non-selected hydraulic fluid during manufacture and to permit sealing, as by a plug, to retain selected fluid prior to marketing the device. This bleeder port preferably is located in a conduit housing part external to either the jack member or the pump member, and is suitably threaded for receipt of a threaded plug.

It may be observed that the jack post of the apparatus is suitably lowered within the jack post housing by merely relying upon the vacuum created within the reservoir of that housing as hydraulic fluid is withdrawn therefrom by elevating the pump piston and therefore increasing the size or capacity of the reservoir in the pump.

That the connecting rod or pump piston actuating rod 46 is hollow or in the nature of a sleeve having longitudinal slots therein is much preferred, as it not only permits of economy in manufacture but retention of strength without the added weight created by a fully solid member. Likewise the nut member or female recess 60 is preferably splined so that projections internally thereof are provided to permit positive contact with a mating member on the crank 30.

Convenience of manufacture further dictates the use of snap-retaining rings as illustrated at the top and bottom end of the pump and the bottom of the jack member. Welding preferably is not used because it tends to distort alignment and tends to distort shape of the tubes. Indeed, it should be observed that the clamp for the jack member is preferably not a clamp welded to the jack member.

As will be evident from this disclosure, the means for elevating and lowering the jack is quite suitably oriented such that the turning of the handle or crank 30 may be accomplished in a horizontal plane, as is preferred. Advantageously the device as mounted on a wheelchair acts upon the frame part of the seat member instead of upon other elements which might be weakened over a period of time and considerable use.

This disclosure is to be construed broadly and illustratively.

That which is claimed is:

1. A hydraulic device comprising (A) hydraulic pump member having an elongated housing with a port end opposite an end equipped with a crank receiving recess, an elongated hydraulic fluid reservoir in one extremity of said housing nearest the port end thereof, the full length of the lateral surfaces of said elongated reservoir being defined by a single sleeve insert snugly fitted within said housing in aligned condition therewithin and held against longitudinal movement therewithin, a plug in the end of said sleeve insert nearest the port end of said housing, a port through said plug and connecting said reservoir to the exterior of said housing, piston means snugly fitted in said sleeve insert and slidably adjustable solely within the length of said sleeve insert to increase and decrease the size of said reservoir and thereby commensurately cause egress and ingress of hydraulic fluid through said port, a piston connecting shaft rigidly fixed to said piston means and having a threaded end member opposite the end thereof fixed to said piston means, said threaded end member being held against rotation within said elongated housing and being adapted to be moved longitudinally as a unit with said piston means therewithin and rotatable threaded means cooperatively acting upon the threaded end member of said piston connecting shaft for actuating adjustment of said piston means, said rotatable threaded means being wholly within the portion of said elongated housing opposite the port end of said housing and being provided with a crank receiving part also wholly within said elongated housing and recessed from the end thereof equipped with said crank receiving recess, said rotatable threaded means being mounted within said elongated housing for rotational movement but fixed therein against longitudinal movement, (B) an elongated hydraulic jack member having an elongated housing, a hydraulic fluid reservoir in one extremity of said jack housing, a port connecting said reservoir to the exterior of said jack housing, and a jack post adapted to telescope slidably in and out of the end of said housing opposite the end thereof containing said reservoir, said telescoping of said jack post being in proportion to the hydraulic fluid passed into and out of said reservoir of said jack housing, (C) a flexible hydraulic conduit connecting the ports of said hydraulic pump member and said hydraulic jack member, and (D) means to actuate said rotatable threaded means and cause movement of hydraulic fluid between the reservoir of said pump member and jack member, thereby to adjust said jack post 01 said jack member in response to rotation of said threadec means.

2. In a wheelchair having a seat member, wheels spaced seat-support side-rods, a collapsible vertically oriented X-frame supporting said seat-support side-rods and a base frame supporting said X-frame and on whicl the wheels of the chair are mounted, the improvemen comprising hydraulic means for narrowing the width c said wheelchair, said hydraulic means consisting esser tially of the device of claim 1, with the elongated housin of the pump member mounted to a base frame part c the wheelchair in essentially vertical orientation and i spaced but fixed condition toward the front and side 4 the seat member of the wheelchair, and with the elo: gated housing of the jack member mounted in fixed co: dition to a base frame part of the wheelchair in a loc tion permitting the jack post of said jack member to a an elongated as an elevator upon one of the spaced seat-support siderods supported on the collapsible X-frame of said wheelchair.

3. The device of claim 1 in which the elongated housing of the pump member is cylindrical and essentially uniform in diameter throughout its length.

4. The device of claim 1 in which the end of the elongated housing equipped with the crank receiving recess is also equipped with a radial bearing, the inner race of which serves as a guide for the shaft of a removable crank insert into said crank receiving recess, thereby to hold said removable crank in alignment during application of force to it for rotation of the rotatable threaded means. i

5. The device of claim 1 in which the rotatable threaded means cooperatively acting upon the threads of said threaded end member of said piston connecting shaft comprises a threaded bolt structure.

' 6.. The device of claim 5 comprising, in addition, a thrust bearing carrying the force transmitted through the bolt from the threaded piston connecting shaft.

7. The device of claim 6 comprising, in addition, a radial bearing having an inner and outer race, to the outer race of which the thrust from said thrust bearing is carried and to the inner race of which the threaded bolt structure is rigidly fixed.

8. The device of claim 7 in which the internally recessed crank receiving part comprises a splined female recess fixed immovable to the inner race of said radial bearing and immovably to said threaded bolt structure,

8 but rotatable with both said'inner race and said threaded bolt structure.

9. The device of claim 8 comprising, in addition, a removable crank member having a splined end for insertion and cooperativeinterlock with said splined female recess, said crank member being adapted to rotate said threaded bolt structure and thereby effect adjustment of the piston in the reservoir of said pump member and responsive movement of the jack post of said jack member.

10. The device of claim 1 in which the reservoir of said jack member is equipped with lateral walls formed of a cylindrical sleeve member inserted in the housing of said jack member.

References Cited UNITED STATES PATENTS 2,219,844 10/1940 Lotter et al. 248-157 2,417,018 3/ 1947 Schroeder 254-93 2,633,578 4/1953 Deves et al. 5-68 2,641,306 6/1953 Lerman 297- 2,684,488 7/1954 Snyder 5-68 3,005,999 10/1961 Brown 5-67 3,023,048 2/1962 Barton 297-330 3,122,395 2/1964 OfiFner 297-45 3,331,614 7/1967 McClintock 297-45 FOREIGN PATENTS 489,056 8/1918 France.

0 FRANCIS K. ZUGEL, Primary Examiner. 

